Platen printing-press.



No. 878,426. PATENTED FEB. 4, 1908. M. ROGKSTROH.

PLATEN PRINTING PRESS.

APPLICATION FILED FEB. 5. 1906.

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PATBNTED FEB. 4, 1908.

M. ROGKSTROH. PLATEN PRINTING PRESS.

APPLICATION FILED PBB.5,1906.

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UNITED STATES PATENT OFFICE.

PLATEN PRINTING-PRESS.

Specification of Letters Patent.

Patented Feb. 4, 1908.

Application filed February 5. 1906. Serial No. 299562- To all whom it may concern:

Be it known that I, MAX RooKsTRoH, a subject of the Emperor of Germany, and residing at Klein-Sedlitz, in the Grand Duchy of Saxony, Germany, have invented certain new and useful Improvements in Platen Printing-Presses, of which the following is a specification.

In platen printing presses as heretofore constructed the platen is moved by oscillating cranks actuated by connecting rods. This arrangement is subject to the disadvantage that the cranks, that is to say, the

shaft connecting them, on account of its inherent elasticity, soon ceases to be perfectly rigid a defect that even the provision of supporting bearings does not obviate.

For presses constructed in accordance with this invention, the cranks hitherto employed and having a common crank shaft all for the purpose of avoiding the defect already mentioned is replaced by a solid body which oscillates in a bearing or recess formed in the upper end of the bedplate and that in combination with the bedplate forms a bent lever that, by means of a stanhope lever is alternately depressed and raised in such a manner that the oscillatory movement of the bent lever is transmitted to the platen through the connecting rods. This bent lever extends over the whole breadth of the press and oscillates at its lower end about a fulcrum which is of circular section, and rests in the recess or bearing already mentioned in the bedplate. The connecting rods may engage directly with the ends of the bent lever which forms laterally projecting studs, or the upper free edge of the bent lever may be constructed as a bearing by which the shaft connecting rods are joined together, this shaft being throughout its entire length supported by the body of the bent lever.

Another constructional form of the invention consists in incasing the shaft which joins the connecting rods completely within the bent lever, thus giving to its bearings the form of a closed sleeve.

The bent lever, which replaces the cranks and crank shaft heretofore usually employed, being composed of solid material is rigid and free fronrall risk of distortion, notwithstanding that it can be so constructed as to be of but little weight.

Figure 1 of the accompanying drawings is a side elevation of a platen printing press showing the bent lever and the connecting rods joined together by a shaft which in this instance is mounted in a sleeve formed on the bent lever. Fig. 2 is a rear view of the same press. Figs. 3 and 4 illustrate parts of a press, in which the bearing wherein the shaft joining the connecting rods is mountedhas the form of a recess or trough open at the back.

a is the frame of the press, b the platen, c the bedplate, e the pitman, f the bent lever with its fulcrum g and bearing sleeve h in which is mounted the shaft "L joining the two connecting rods (l. The stanhope lever e is by means of eyes Z flexibly connected with the bent lever and is actuated in the usual manner. As soon as the bent lever becomes vertical the platen will move towards the bedplate and the pressure exerted at the instant of complete contact of the platen is, as a result of the action of the bent lever very great.

Figs. 3 and 4 respectively illustrate the positions of the bent lever when the platen is in contact with and withdrawn from the bedplate. They also illustrate the construction wherein the bearing of the shaft joining the connecting rods consists of a trough or recess formed in the bent lever and open at the back.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is In a platen printing press, a platen, a pair of actuating rods therefor, a solid member the length of which corresponds to the space between the said rods, said member having a cylindrical lower edge, a bed-plate having a cylindrical groove extending over the whole breadth thereof, said cylindrical edge of said member adapted to oscillate in said groove, a pitman, and means for connecting said member at its upper side ends to the actuat ing rods and at its center to said pitman.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

MAY ROCKSTROH.

I/Vitnesses:

HENRY IIAsPER, WOLDEMAR I'IAUPT. 

